Continuous glider target pickup unit



March 8, 1949. R. B. COTTON 2,464,073

CONTINUOUS GLIDER TARGET PICKUP UNIT Filed March 51, 1947 '7 Sheets-Sheet 1' IIIZ , IN VEN TOR.

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CONTINUOUS GLIDER TARGET PICKUP UNIT Filed Mar ch 31 1947 7 Sheets-Sheet 5 INVENTOR. @5527- 5, CarroA/ H15 Ar raZ/VEX March 8, 1949. R. B. COTTON 2,464,073 CONTINUOUS GLIDER TARGET PICKUP UNIT Filed March 31, 1947 '7 Sheets-Sheet 4 /-//s ATraZA/E Y March 8, 1949.

R. B. COTTON CONTINUOUS GLIDER TARGET PICKUP UNIT '7 Sheets-Sheet 5 Filed March 51, 1947 Ill INVENTOR. F0552? 5,, C 0 TTOA/ BY 'H/s Arroz/vev March 8, 1949.

R. B. COTTON 2,464,073

CONTINUOUS GLIDER TARGET PICKUP Filed March 31, 1947 UNIT 7 sheeis-shee't 6 INVENTOR. ,Foa er 5 C 0 r 70M ///5 ATTOZNEY 7 Sheets-Sheet '7 INVENTOR.

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Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE CONTINUOUS GLIDER TARGET PICKUP UNIT RobertB. Cotton, Lansdowne, Pa., assignor to All American Airways, Inc., a corporation of Delaware application March 31, 1947, Serial No. 738,373

15 Claims. (Cl. 258-12) The present invention relates to air pick-up and is concerned primarily with the problem of making successive pick-ups of gliders without landing.

At the present time, the personnel of our is destroyed and there are times when the towline the pick up apparatus so as to ready it for the 1 next pick up.

With the foregoing conditions in mind, this invention has in view as its foremost objective, the provision of pick up equipment adapted to be attached to an air-craft for making successive pick a ups of aerial targets without landing.

The type of target with which this invention is particularly concerned is a glider. The apparatus of this invention is designed primarily for use with a target of this type. A further object of the invention is the provision of a unit which is subs'tantially complete in itself and which is adapted to be attached to or detached from an aircraft with a high degree of simplicity.

A further object is the provision of such a unit which includes means for controlling the payin out and reeling in of a towline to which the target is attached. Inasmuch as it is important that the pilot of a plane know the relative position of the target being towed, it is important to provide instruments which will give him this information. Accordingly, a further object lies in the provision of an electrical system providing gauges in the plane, together with instruments in the unit, for indicating the rate at which the towline is payed out and the length of the line which has payed out. This is accomplished by the use of Se1syn motors which are readily adapted for the quick assembly and detachment above referred to.

It often becomes necessary for the power of the plane to cut the towline so asto release a damaged target. A further end in view is the provision in an aircraft including a unit of the character aforesaid of explosive means for cutting the towline and which means is included in the electrical senting' .an erected" loop to which the object to be picked up is attached and a contact arm on the pick-up aircraft, and which arm carries a releasable hook attached to the towline, are essential elements to a pick up apparatus. This invention proposes to follow this technique. However, in order to provide for successive pick ups Without landing, it is necessary that the contact arm carry a magazine of pick-up hooks. A further object, therefore, is the provision in air pick-up mecha- 1 nism of the type indicated, of a contact arm, to-

gether with a magazine including a supply of pick-up hooks, with means for urging each hook successively into effective position.

For the initial pick-up of any series, it is entirely practical to provide the towlines with a knot obstruction or other comparable element which is engaged by a hook, so as to fix the connection between the two. However, once the line is severed, it becomes necessary to provide means for establishing a fixed engagement between the hook and the line. Accordingly, a further objective is the provision, in air pick-up equipment,- of a towline on which is threaded a plurality of pick-up hooks and each of which includes means for engaging the line at a point closely adjacent to where it is severed. Whether the line is shot away or cut by an explosive cutter, the end of" the line is left in a frayed or distorted condition which is adapted to be caught by a so called snarling element on the hook. Particular features and advantages of the invention are tied in with the provision of this particular element.

In providing a unit of the character above indicated it becomes important to accurately control the reeling in and paying out of the towline. Another objecttherefore, is the provision of a unit of the type aforesaid which includes a winch, together with an impeller for rotating the winch under air power, together with new and improved level wind for controlling the winding of the towline on the winch.

Various other more detailed objects and ad vantages of the invention such as arise in connection with carrying out the above noted ideas in a practical embodiment will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

The invention, therefore. comprises a pick-up unit adapted to be quickly attached to or detached from an aircraft and which includes a Winch, control instrumentalities therefor, and a towline that is taken up on said winch, together with a contact arm carrying a magazine of pickup hooks, each of which includes means for fix ing an. engagement with the towline on which they are threaded. For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein:

Figure 1 is a perspective, largely diagrammatic, showing an aircraft about to pick up a glider target in accordance with the principles of this invention.

Figure 2 is another perspective similar to Fig. 1 showing the relation of the parts immediately after the pick-up.

Figure 3 i a side view, somewhat diagrammatic, showing the condition when the towline is severed.

Figure 4 is a view similar to Fig. 3, depicting a damaged glider target.

Figure 5 is another view similar to Figs. 3 and 4 illustrating the severing of the towline at the aircraft by an explosive cutter.

Figure 6 is a side view showing the unit of this invention applied to an aircraft.

Figure 7 is a side view showing the attachment to the glider.

Figure 8 is a longitudinal section through the unit bringing out details of the mechanism therein.

Figure 9 is a transverse section taken about on the plane represented by the line 99 of Fig. 8.

Figure 10 is a front view of the instrument panel for the unit.

Figure 11 is a wiring diagram for the unit and associated instrumentalities.

Figure 12 is mostly a longitudinal section through one end of the contact arm with a portion shown in elevation, being taken about on the plane represented by the lines |2 -|2 in Figure 13.

Figure 13 is an end elevation of the contact arm, and.

Figure 14 is a detailed perspective of the free end of the contact arm.

Referring now to the drawings wherein like reference characters denote corresponding parts, and first more particularly to Figs. 1 and 2, a surface from which pick-ups are to be made is referred to generally as S. This surface may be any appropriate ground location or the deck of a ship. The target being picked up is shown in the form of a glider G and may be any type of glider found suitable for target purposes. A ground station is identified in its entirety by the reference character A. This station A comprises spaced poles II] which hold in erected position a loop having a top ply that is tensioned whereby it is adapted to be engaged by a contact arm and pick-up hook as will be later described. A line I2 connects the loop II to the glider G. A bridle such as shown at I3 in Fig. 7 may be employed to establish the connection with the glider and at the same time maintain the relation necessary for good flying characteristics.

An aircraft which is to be used in picking up and towing of gliders is designated P. The aircraft P includes the usual elements found in an airplane, but this invention is concerned particularly with the fuselage designated I4. The unit which is attached to the aircraft P for the purpose of accomplishing successive pick ups of the gliders G is identified in its entirety by the reference character U. This unit U houses substantially all of the mechanisms and devices necessary to achieve the successive pick-up operations hereinafter to be described.

Referring now more particularly to Figs. 8 and 9, the unit U is shown as comprising a housing that is divided into three sections. Thus, it is made up of a nose I5, a tail section I6, and an intermediate or body section IT. A head or partition I8 divides the sections I5 and I1, while a similar partition I9 marks off the sections I6 and I1. It will be noted that the outer casing of the intermediate section I! carries hooks or bails 20 which are employed to secure the unit U to the underside of the fuselage I4 as is clearly shown in Fig. 6.

Mounted for rotation between the heads I8 and I9 is a drum 2| on which is wound a towline 22, one end of the towline being anchored to the drum in a well-known manner. The line 22 is coiled between end flanges 23 in an orderly arrangement as will be later pointed out. A gear 24 is drivably associated with the drum 2| and is driven by a pinion 25, carried by a shaft 26.

An air driven impeller referred to in its entirety by the reference character I is mounted in the nose section I5 and serves to derive power from the motion of the aircraft P through the medium of the adjustable vanes 21. This power is transmitted through the bevel gears shown at 28 to the shaft 26. Air driven impellers of the type depicted at I are generally known. Such an impeller is illustrated and described in detail in the co-pending application of Robert B. Cotton, Serial No. 693,044, filed August 26, 1946, for Air driven impeller. So far as this invention is concerned, it is notable that the vanes 21 may be adjusted anywhere from a fully feathered position in which no power is developed, up to an angular position of maximum power. This will be controlled by the operator as will be hereinafter pointed out.

Extending between the heads I8 and I9 is a guide rod 29 and immediately therebeneath is a double threaded screw 30. A slide 3| is fitted over the guide 29 and has parts which cooperate with the threads of the screw 30 so that as the latter is rotated the slide is caused to move alon the drum 2|. The towline 22 passes between guiding rollers 32 which are carried by the slide 3|. Thus, as the slide 3| is moved longitudinally, the line 22 is wound on the drum 2| in an orderly manner. The screw 30 may be driven from the shaft 26 and pinion 25 as illustrated in Fig. 8. A supporting arm 33 extends between the heads I8 and I9 and carries a bracket 34 on which is mounted a sheave 35. The towline 22 passes around the sheave 35 and extends through the partition I9 and over a second sheave 36 that is mounted on a bracket 31 carried by the head I9 and which extends into the tail section I6.

A contact arm 38 of tubular construction carries at its upper end a bell crank 39. The bell crank 39 has an arm 40 which is pivotally attached to the bracket 31 and long arm 4|. The bell crank 39 also carries a gear sector 42 with which meshes a pinion .43 that is driven by a motor represented diagrammatically at 44. This motor 44 is shown in the wiring diagram of Fig. 11.

Mounted within the tail section I6 is a dash pot 45 having a piston 46 which is connected to the free end of the bell crank arm 4|.

After passing over the'sheave 36 the tow line 22 passes down into the bottom of the tubular slot 48, that opens into the free end edge of the tube. This free edge carries inwardly projecting retaining tabs 49 and 50. A supply of pick-up hooks 5| have cylindrical body portions 52 which are received in the bore of the tube 38, and bills 53 which are positioned exteriorly of the tube 38 and connected to the cylindrical body portion 52 by necks that are received in the slot 41.

As clearly shown in Fig. 14, a plurality of these hooks 5| are positioned within the end of the tube 38 and urged against the retaining tabs 49 and 50 by an expansion spring 54. The latter bears against a spring follower 55 formed with a central opening to accommodate the towline 22 and which spring follower in turn engages the innermost of the hooks 5!.

Upon referring to the righthand side of Fig. 12 wherein one of the hooks Si is shown in section, it will be noted that each cylindrical body portion 52 is formed with a center bore 56 that is; enlarged at one end to provide a socket 51 and is surrounded at the other end by a lip 58. Secured around the lip 58 is a snarling member 53 having a plurality of converging spring fingers, the extremities of which are spaced sutficiently to allow for the passage of the line 22 therethrough.

The end of the line 22 originally carries adjacent to its extremity some form of obstruction, such as the ball shown at 6!. This ball is engaged by the snarling member 59 to prevent the end hook in from pulling off the line. fter the line is severed for any reason, its end will be distorted or frayed, in which condition it is readily adapted to have the spring fingers Bil of any subsequent hook catch thereon.

Upon referring to Fig. Id, it will be noted that the lower end of the contact arm 38 is supported by the big-ht of a suspension line 52. This limits downward movement of the contact arm 38.

Upon referring to Fig. 8, it will be noted that the unit U carries on its upper side in close proximity to one of the bails 26, an electrical connecting element 63. A corresponding element (not illustrated) is mounted on the under side of the fuselage it, and in proper position so that when the unit U is mounted on the fuselage by the bails 28, the two connecting elements meet and complete the several electrical circuits of the unit and ofthe plane.

Upon referring to Fig. 6, it will be noted that the rear part oi the fuselage 14 carries a plurality of explosive cable cutters shown at 54'. Any desired number of these cutters may be included. When one is exploded, it should be effective to cut the towline 22 when the latter is in its immediate Droximity as will be the condition during a towing operation. Explosive cable cutters of this generaltype are generally known. One such cutter is fully illustrated and described in the application of Arthur B. Schultz, Serial-No. 558,- 022; filed October 10,1944, now Patent No. 2,460,- 194, dated January 25,. 1949, and entitled Apparatus for severing tow lines and the like. The cable cutters 64 are electrically detonated and. the control wires therefor are includedinthe electric system now to be described.

Upon referring to Fig. 11, the various electrical devices, represented symbolically within the broken line rectangle, are assembled substantially at the control panel which is shown at 65in. Fig 10. The cable, cutters B4 are included inthe fuselage M as. above described, and the other 6 electric instrumentalities are included within the unit U.

The motor 44 which raises the contact arm 38 is within the unit U. Conductors 66 extend through the connection 63 to the instrument panel where they are connected to a control switch 67. Another electric motor 68 is included in the nose section l5 and is operatively connected with the vanes 27 so as to control the pitch thereof. Conductors 69 extend from the motor 68 through the connection 63 to the panel 65 where they are connected to a control switch 10.

A Selsyn motor H is included in the unit U and is affected by the length of cable which is payed out from the drum 2| A corresponding Selsyn motor 12 is carried by the panel 65 and is operatively connected to the gauge 11. The Selsyn motor 16 is carried by the unit U and is affected by the rate at. which the towline 22 pays out. Conductor It couples the motor 15 and 76' in a conventional manner.

Wires is extend from the. cable cutter 64 to the bank of control switches shown at. 80 on the panel 65.

Operation While the operation of the above described mechanism is believed to be apparent from the description of the various elements, it will be noted that when a glider target G is to be picked up, the ground station A is first erected on the surface from which the. pick-up is to be made. This may be the deck of a ship or another appropriate location. With. the ground station erected, the loop 9 l presents, a top ply that is tensioned and adapted to be engaged by pick-up arm and pick-up hook. The line I! connects the loop 1 I to the glider targetG.

The operator in the plane P first fills magazines M with an adequate supply of the hooks 5!. The contact arm 38 is now lowered. into the depending position illustrated' in Fig. 1'. In this position the outermost hook 5i, i. e., the one at the end of the arm, will be twisted about under the influence of cam slot 48- into' a position in which the bill 53' extends downwardly in contrast to the upper position of the remainder of the bills.

The operator now flies the plane in so that the contact arm, 38. engages the top ply of the loop ii. The loop H slides down the under side of the arm 33 until it is engaged and" caught'by the bill 53' of the hook 51 at the end of the arm. This action causes the hook 5i to overcome the resistance of the retaining tabs 49' and 58 and come free of the arm. The towl'ine 22' is now connected to the loop I! and pays out from the drum 2!. The. operator may now avail of the control switch 10 to feather the vanes 21' and thereby cause the impeller I to generate the. de sired amount of' power which. controls-the cable payout and reel the cable in. when the occasion demands.

With the target. glider G- a. safe distance behind the. plane P, it. may be. shot. at by those undergoing training.v This: may result. in the towline 221itselt being severed, as, shown in Fig. 3, or thetarget itself. may be damaged,.as illustrated in Fig. 4. Int'ne latter event-,the. operator. may avail. of, the. control switch. 6-] to turn on the motorv t tandraise thev arm. 38.. Thisbrings the towline 'al'lintov close proximity to-the. bank of cable cutters.64,.whereupon one of them-maybe detonated. toseven the towline and tree it. of: the

damaged target. The operator may now lower the contact arm and the apparatus on the plane is in condition to make another pick-up, because when the hook at the free end of the arm is pulled loose, the spring 54 moves the next hook into effective position, and when this hook is pulled free, as by the next engagement with the 100p of the ground station, the spring fingers 60 of the snarling element 59 catch on the distorted end of the towline 22 and fix the connection between the hook and the towline.

It is evident that the unit U may be removed as a unit, because the several electrical circuits may be broken at connection 63 and the bails 20 released from the fuselage M. The unit may be attached to any plane which is adapted to pickup operations by fairly simple changes that are easily carried out.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact construction illustrated and described because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In air pick-up apparatus, a tubular pick-up arm, means for mounting one end of said arm on an aircraft, a magazine at the other end of said arm, a supply of releasable pick-up hooks in said magazine, and means for feeding said pick-up hooks into effective position.

2. In air pick-up apparatus, a tubular pick-up arm, means for mounting one end of said arm on an aircraft, a magazine at the other end of said arm formed with a cam slot, a supply of pick-up hooks in said magazine and engaging said cam slot, and spring means urging said hooks into effective engagement with said cam slot.

3. In air pick-up apparatus, a tubular pick-up arm, means for mounting one end of said arm on an aircraft, a magazine at the other end of said arm, a supply of releasable pick-up hooks in said magazine, yieldable means retaining said hooks in said magazine and adapted to be overcome by the force of a pick-up to release a hook at the end of said magazine, and spring means urging said hooks against said releasable means.

4. In air pick-up apparatus, a tubular pick-up arm, means for mounting one end of said arm on an aircraft, a magazine at the other end of said arm, a supply of releasable pick-up hooks in said magazine, each of said hooks being formed with a central opening, a line passing through said openings, and means carried by each of said hooks around said opening for catching on to a frayed part of said line.

5. In air pick-up apparatus, a tubular pick-up arm formed with a cam slot adjacent to one end, a pick-up hook comprising a main body part positioned in the bore of said tubular arm and formed with a center opening, a bill positioned exteriorly of the tubular arm, and a neck connecting said bill and main body part and positioned in said cam slot, spring means in said arm urging said hook toward the free end thereof, a line threaded through the opening in said main body part, and means on said body part to engage a frayed part of said line to prevent relative movement between said hook and line.

6. In air pick-up apparatus, a tubular pick-up arm formed with a longitudinal slot adjacent to one end and a cam slot communicating with said longitudinal slot, a plurality of pick-up hooks in said arm, each of said hooks carrying a projection fitting in said slot, and yieldable means urgeing said hook toward the end of said arm.

7. In air pick-up apparatus, a tubular pick-up arm formed with a longitudinal slot adjacent to one end and a cam slot communicating with said longitudinal slot, a plurality of pick-up hooks in said arm, each of said hooks having a main body part in said arm, a bill exteriorly of said arm, and a neck connecting said bill and main body part, with the neck positioned in said slot, and a spring urging said hooks toward the end of said arm whereby the hook in end position is subject to the effect of said cam slot. I

8. In air pick-up apparatus, a tubular pick-up arm formed with a longitudinal slot adjacent to one end and a cam slot communicating with said longitudinal slot, a plurality of pick-up hooks in said arm, each of said hooks having a main body part in said arm, a bill exteriorly of said arm, and a neck connecting said bill and main body part with the neck positioned in said slot, spring means urging said hooks toward the end of said arm, a line extending through said arm and on which said hooks are threaded, and means carried by each of said hooks for engaging a frayed part of said line.

9. In air pick-up apparatus, a tubular pick-up arm formed with a longitudinal slot adjacent to one end and a cam slot communicating with said longitudinal slot, a plurality of pick-up hooks in said arm, each of said hooks having a main body part in said arm, a bill exteriorly of said arm, and a neck connecting said bill and main body part with the neck positioned in said slot, spring means urging said hooks toward the end of said arm, yieldable means for holding said hooks in said arm against the influence of said spring means, a line extending through said arm and on which said hooks are threaded, and means carried by each of said hooks for engaging a frayed part of said line.

10. In air pick-up apparatus, a pick-up aircraft, a unit detachably carried by said aircraft, a pick-up arm pivotally mounted on said unit, a magazine of pick-up hooks included in said arm, a winch in said-unit, and a line on said winch and threaded through said hooks.

11. In air pick-up apparatus, a pick-up aircraft, a unit detachably carried by said aircraft, a pick-up arm pivotally mounted on said unit, a magazine of pick-up hooks included in said arm, a winch in said unit, an air impeller operatively associated with said winch, a line on said winch and on which said hooks are threaded, and means on each of said hooks for engaging a frayed part of said line.

12. In air pick-up apparatus, a pick-up aircraft, a unit detachably carried by said aircraft, a pick-up arm pivotally mounted on said unit, a magazine of pickup hooks included in said arm, a winch in said unit, an air impeller operatively associated with said winch, a line on said winch and on which said hooks are threaded, means on each of said hooks for engaging a frayed part of said line, and an explosive cable cutter carried by said aircraft in a position to be effective on said line beyond the free end of said pick-up arm.

13. In air pick-up apparatus, a pick-up aircraft, a unit detachably carried by said aircraft, a pick-up arm pivotally mounted on said unit, a magazine of pick-up hooks included in said arm, a winch in said unit, an air impeller operatively associated with said winch, a line on said winch and on which said hooks are threaded, means on each of said hooks for engaging a frayed part of said line, a battery of explosive cable cutters at the rear part of said pick-up aircraft, and means for setting 01f said cable cutters individually.

14. In air pick-up apparatus, a unit, means for detachably securing said unit to an aircraft, a winch in said unit, an air impeller in said unit operatively connected to said winch, a level Wind associated With said winch, a line taken up on said Winch and passing through said level Wind, a tubular pick-up arm pivotally connected at one end to said unit, a magazine of pick-up hooks in said arm and threaded on said line, yieldable means for retaining said hooks in said arm, and means on each hook for engaging a frayed part of said line.

15. In air pick-up apparatus, a unit, means for detachably securing said unit to an aircraft, a winch in said unit, an air impeller in said unit operatively connected to said Winch, a level wind associated with said winch, a line taken up on said winch and passing through said level Wind,

10 a tubular pick-up arm pivotally connected at one end to said unit, means for limiting downward movement of said arm, means for raising said arm, a magazine of pick-up hooks in said arm and threaded on said line, yieldable means for retaining said hooks in said arm, and means on each hook for engaging a frayed part of said line.

ROBERT B. COTTON.

REFERENCES CITED iThe following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,326,732 I-Iolme Dec. 30, 1919 2,295,537 Anderson Sept. 15, 1942 2,373,414 Plummer Apr. 10, 1945 2,433,448 Gottschall Dec. 30, 1947 FOREIGN PATENTS Number Country Date 334,044 Germany Mar. 9, 1921 

